Physicochemical and biocompatibility analyses of surface-coated IN0.57SB0.43 thin films under aqueous conditions

Abstract

InSb-based devices embedded in the human body can be utilized for biological applications, including the detection of biomagnetic fields owing to the high electron mobility of InSb, which is a suitable magnetic resistance element. In this study, the aqueous stability of In[Formula: see text]Sb[Formula: see text]/quartz prepared by RF magnetron sputtering was evaluated as the initial stage for use in biomedical devices. In[Formula: see text]Sb[Formula: see text]/quartz was coated with (3-mercaptopropyl) trimethoxysilane (MPT), as InSb was not stable under aqueous conditions. MPT coating did not affect the thin-film properties (such as surface morphology, crystal structure, and electrical properties) of In[Formula: see text]Sb[Formula: see text]/quartz. A cell viability assay confirmed the lower cytotoxicity of MPT-coated In[Formula: see text]Sb[Formula: see text]/quartz than that of bare In[Formula: see text]Sb[Formula: see text]/quartz because the MPT coating reduces the elution of indium from In[Formula: see text]Sb[Formula: see text]/quartz. In addition, the MPT coating essentially suppressed the deterioration of the thin-film properties under simulated physiological conditions. Therefore, MPT-coated InSb thin films are expected for use in temporary implanted biomedical devices.